RA Q51
0. The process not needed in experimental research is:
- Option : D
- Explanation : In experimental research, the essential processes are:
✅ Observation — to note effects of the experiment
✅ Manipulation and replication — manipulating variables and repeating to check reliability
✅ Controlling — controlling extraneous variables to ensure internal validity
However, reference collection (i.e., gathering reference materials or literature) is not an actual process step of conducting an experiment itself, though it can support the background.
So the correct answer is:
D. Reference collection
